1. Field of the Invention
The present invention relates to a process for manufacturing composite thermal insulating systems by means of an organic adhesive or filler material serving as an adhesive for insulating boards to be attached to a facade or as a filler material for evening out facade unevenness prior to attaching the insulating boards or for producing a reinforcing layer on the attached insulating boards.
2. Description of the Related Art
In practice, such organic adhesive and filler materials are preferably processed by means of machines. When manufacturing composite thermal insulating systems which have been known for a long time and are disclosed, for example, in DE 32 02 960, insulating boards, particularly of extruded hard polystyrene foam, are placed on brickwork using an adhesive or filler material. Any unevenness of the brickwork is compensated by the adhesive or filler material. The insulating board is protected against weathering by means of a multilayer reinforced plaster coating, composed of a reinforcing layer which, in turn, is composed of a reinforcing substance and a reinforcing fabric, and a cover coating of, for example, a hard artificial resin plaster, and possibly with an additional first coating on the reinforcing layer.
In practice, predominantly cement-containing adhesives have been used for mounting the composite thermal insulating systems. The formulas of the cement-containing adhesives made it possible to apply the adhesives in thicker layers and thereby to compensate the unevenness of the background. It is possible in this manner to produce a flat facade by means of the insulating boards used for this purpose.
Particularly when refurbishing old buildings, the unevenness of the facade surface means that significant amounts of adhesive or filler material are required for evening out the surface.
Cement-free plastic-based adhesives are also already known in the art for mounting composite thermal insulating systems. The formulas are based on aqueous polymer dispersions on the basis of acrylate monomers, methacrylate monomers, vinyl acetate monomers, styrene monomers, butadiene monomers, ethylene monomers, versatic acid ester monomers and combinations thereof.
For example, DE 44 02 688 discloses an aqueous dispersion adhesive for gluing insulating boards, such as hard polystyrene foam boards. However, these polymer-bound adhesives cannot be applied in thick layers for evening out the background because they dry only slowly underneath the insulating boards. In addition, the adhesives are very difficult to process when they have the required consistency and are uneconomical because of the high quality of material that is required. For this reason, such adhesives have in the past only been used on smooth surfaces on which they could be applied in thin layers. When applied in thin layers, such adhesives dry over a normal period of time and their use is still economical.
Therefore, it is the primary object of the present invention to propose a process which makes it possible to use organic adhesive or filler materials by improving their properties in such a way that a good volume filling capacity, quick drying, long service life and cost reduction are achieved as compared to conventional organic adhesive or filler materials.
In accordance with the present invention, the adhesive or filler material is foamed prior to its use.
It has been found to be particularly useful if the material is used with a wet density after foaming of 0.3 to 1.2 kg/l, preferably 0.6 to 0.9 kg/l.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the descriptive matter in which there are described preferred embodiments of the invention.
In accordance with a very advantageous feature of the process of the invention, foaming is effected by supplying pressurized air or another gas. It has been found that the adhesives which form stable foams as a result of the supply of air can be applied in thick layers. Consequently, this simplifies the processing of the adhesives and quick drying takes place behind the insulating boards. These adhesives then make it possible to even out the boards to obtain a flat surface.
Foaming of the material produces the result that the significantly increased volume makes it possible to even out unevenness using a much smaller quantity of material. For example, a compound for improving the adhesive, such as a resin dispersion, may also be added with the foaming agent.
It has been further found that these polymer-bound foamed adhesive or filler materials constitute excellent reinforcing substances. The foamed adhesive or filler materials form a creamy layer which can be processed very easily. In addition, significantly less material is also required for reinforcing a composite thermal insulating system.
The foamed adhesive or filler materials used in accordance with the process of the present invention make it possible to manufacture a composite thermal insulating system in which the organically bound adhesive for the insulating boards and the reinforcing substance are of the same material, thick layers can be processed very easily and the adhesive or filler materials dry quickly.
Foaming of the organic adhesive or filler materials is preferably carried out by machines. Initially, the material is conveyed by means of a mixing and conveyor pump, for example, a rotary displacement pump as it is described in DE 295 11 966, from a container, for example, a silo, through a conveying hose to a spray pistol and is sprayed onto the facade. During the conveying process, the foaming agent or the compressed air or the gas and other components can be added at the conveying pump or at the spray pistol.
Suitable as foaming agents are preferably ethylene and propylene polymers from ethylene and propylene oxide, alkyl-di-glycolether sulfate sodium salt, sodium lauryl sulfates or non-ionic tensides, such as fatty alcohol ethoxylates. An additional regulation of the foam structure can be achieved by adding silicon oils and stabilization can be achieved by foam stabilizers, such as sodium sulfosuccinamates.
Examples of an adhesive or filler material suitable for gluing and reinforcing appear below.